INFLAMMATION. 51 



Explain the constitutional causes, the trophic causes, the 

 metastatic causes, and the spontaneous causes. 

 The constitutional causes of iuflammation are certain changes 

 in the composition of the blood. The trophic causes are supposed 

 to take place through the nervous system. The metastatic causes 

 are where a disease shifts from one place to another, as pneumonia 

 followed by laminitis. Spontaneous inflammations do not exist, 

 and the term should not be used, although when we are unable to 

 attribute any cause we say spontaneous, in order to differentiate. 



What are the clinical symptoms of inflammation ? 



These are called local or cardinal symptoms, and are redness, 

 swelling, ptain, and heat; to these we add a fifth — impaired function. 



The redness is due to what ? 



It is due to an increase in the amount of blood in the part. 

 The presence or absence of redness is not proof of the presence or 

 absence of inflammation. 



What causes the swelling ? 



First, the congestion of the vessels of the part, and, secondly, 

 the exudation of the liquor sanguinis. 



How is the pain produced? 



It is caused by pressure on the nerves by the inflammatory exu- 

 dation, and is called inflammatory pain. Pain is not always signifi- 

 cant of inflammation, as neuralgic pain or the pain in colic. 



What causes the heat? 



The increase in the amount of blood in the part, causing in- 

 creased chemical changes. 



The impairment of function is how explained ? 



This cannot always be appreciated directly, but is of much 

 clinical importance. In brain troubles, coma or delirium; in bowel 

 trouble, diarrhoea ; in stomach trouble, anorexia. 



Enumerate some of the general symptoms of inflamma- 

 tion. 



The general or constitutional symptoms vary with the kind, 

 form, and seat of the inflammation. They are very important and 

 are indicative of symptomatic fever, showing the nature of the dis- 



